-Suggestions-
***ROGUE***
Sneak attack doesn't seem to upgrade to 2d6 at level 3 as far as Ive seen. Thief does get an extra bonus action which can be used for another offhand attack which slightly makes up for this, however arcane trickster doesn't which makes rogue pretty underpowered.
In general, sneak attack seems poorly implemented. You can't sneak attack with your offhand attacks which reduces your damage output by quite a bit. Maybe it would be possible to make sneak attack a toggle-able skill in the same vein as attacks of opportunity ( since you should be able to sneak attack again outside your turn on an AoO). Just let it pop if the conditions of 1.5m ally or advantage are met!
I came to complain that this rogue action economy is pretty badly broken with cunning action granting not only a Dash, disengage or hide but a 3rd attack, which means rogues are essentially getting 3 attacks at 2nd level and we should all be rogues.
and yeah, agree that the sneakattack should be a toggle for attack that gets consumed on the first time you hit with an attack, meaning that I could opt not to sneak attack with my main hand, kill a dude, finish my move, toggle on the sneak attack, hit with my offhand bonus and get my sneak damage assuming that the dude is threatened, surprised or otherwise granting advantage. I also seem to be able to threaten all by my lonesome for sneakattack, but I havent verified this.
